I have a stock SRW 2006 that I use to tow my 14K pound 5th wheel. It has the stock 18" wheels with 33" tires with 3.73 gears. I was thinking of more power but I think re-gearing and keeping the engine stock would be a better way to go. I am thinking 4.30 gears would help hold the truck overdrive while towing. Has any one re-geared the FORD 10.5 differential?

 

I could be wrong but I think you could get a diff out of a salvage yard with 4.10 or 4.30 gears and swap the whole thing for less than regearing. I thought about doing the same thing when I had my f250 but I seem to recall that was what others advised. I could be wrong. I'm sure someone more knowledgeable will offer up an opinion. I ended up getting an f350 drw with 4.10 to tow my 14.5k fifth wheel

 

Question, don't you have to match gearing with your front differential in a 4X4. So you would have to change both, right?

 

4x4 needs matched gear sets... yes

 

Thanks I'll add that to my slim knowledge bank ;-)

 

I have an 05 Dually with 430 gearing and tow a 18,000 5ver The truck pulls very well and holds overdrive well. I towed my trailer once ( same route) with my brothers 04 dually and he has the 410 gearing and the truck did well also but seemed a little sluggish. If it were me and I were not worried about a drop in fuel mileage and were changing gears I would go 430. If you find them to low just go to bigger tires

 

Salvage is definitely the economical away to go. For good gears, r&r you're looking at 5 or 6 grand (last time i looked wich was a good while ago) at a good shop. What issues are you seeing pulling 14k with 3.73s?

 

5 to 6k? Lol, no way.

Let me guess, studding a 6.0 costs 12k?

 

5200 for me
Gears alone would be about 3 to 4k (both sets) atleast what I've looked at and that's me buying them.

 

I have NO idea where you are shopping for gears but 430's for a Dana 60 ( front) and sterling 10.5 rear are $600 for the set on almost any site. My Locker for my front axle cost less than $1200.

 

I got an estimate of $2335.0 from 4WHEELPARTS, that is for Yukon 4.30 Gears installed. I figure they have a 4WHEELPARTS store in every town, so I can get warranty where ever I go.

I found a good website for calculating tire size vs gear ratios, www.ringpinion.com. It has a bunch of calculators to choose from, I used the TireHeight calculator. From that calculator I figured GearRaio/3.73/, TireHeight/33/, Speed/70/ and the calculated RPM is 1861. With the lower gears I figured GearRaio/4.30/, TireHeight/33/, Speed/70/ and the calculated RPM is 2145. It also posted the best RPM's for towing for the 6.0L diesel to be 1900-2400. I also used the 5R110W torqshift transmission overdrive ratio of 0.71/1 in these calculations. My experience when towing with my 6.0L is that RPM's are lower than the opimal RPM's of 1900-2400. Having the lower than optimal RPM causes the tranny to down shift a lot more during towing. I would rather run at 2145 and hold the overdrive when towing.

 

My apologies on the $$ i posted up. I looked back at my list and it was yukon stuff and included new carriers as well as gears and total was just about 3k.

 

Here is another handy calculator for gear ratios:
Gear Ratio Calculator

I got a quote of just under $1,800 for 4.30 gears and a Detroit Locker in the axle of my 2wd.

 

I would take a page from the book of Magnolia Tom 3:4 if your dually is used as a daily driver. Tom has 4.10 gears in his F350 and in it's mostly stock setup, it's very capable of pulling his fifth wheel while delivering good fuel economy otherwise.

However, if your dually's sole purpose is to pull that fifth wheel up some lengthy grades, I'd opt for 4.30 gears.

Beginning in 2005, Ford began offering the "Tow Boss" package on F350 DRW truck's equipped with the 6.0. This package included 4.30 gears and I believe better springs as well.

TOWBOSS PACKAGE (53B)
Availability:
• Optional on DRW
• Requires Power Stroke® 6.0L diesel engine (90P), TorqShift™ automatic
transmission (44B) and TowCommand System (91T)
Includes:
• 4.30 Limited Slip Rear Axle
• Increased GCWR to 26,000 lbs.

 

2006 f 350 6.0 will i see a difference if i went from 3.73 gears to 4.11 gears on towing a fifth wheel 17000 lbs.?
Or should i install 4.30?
truck is single rear wheel.